Concentric conductor system



March. 14, 1933. A. CARPE El AL CONCENTI'RIC CONDUCTOR SYSTEM Filed May22, 1930 Dielectric Sheet Jhbz'm semisect twisted toyet 7Vlded, selderedor bva ed INVENTORS v Z r e QF/ZZL' e ATTORNEY Patented Mar. 14, 1933UNITED STATES PATENT orrics ALLEN CABPE, NEW YORK, N. Y AND FRANK A.LEIIBE, OF DUNELLEN, NEW JERSEY,

ASSIGNOB8 '10 AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORA- 'IIONOF NEW'YOBK commmcrc connno'ron sysrm Application m m 22,

This invention relates to concentric conductor systems, and particularlyto the mechanical and electrical construction of such systems. A.concentric conductor system as ordinarily constructed comprises innerand outer tubular conductors concentrically arranged and suitably spacedfrom each other by means of insulating washers or elements strung alongthe inner conductor. The two conductors are, of course, so connectedthat one acts as a return for the other. In accordance with the resentinvention, it is proposed to simpli y the construction by using spirallyarranged dielectric spacing material instead of spaced washers orequivalent devices for se arating the inner and outer conductors. his isaccomplished by forming the inner tubular conductor of two semi-circularpieces of tubin with their fiat sides abutting, and with die ectricmaterial in the form of thin, flat sheets laid between the two pieces oftubing, the flat sheet of dielectric material being of greater widththan the diameter of the inner conductor. The elements thus arranged aretwisted so that the dielectric sheet is in the form of a spiral. Theouter conductor will then have an inner diameter corresponding to thediameter of the spiral dielectric. If desired, the outer conductor maybe formed from a flat sheet of copper or other suitable conductivematerial, bymeans of a die which folds the .flat conductive materialwith its edges abutting to form-the tube, the inner core comprising thedielectric element and the two semi-circular ieces of tubing being fedin' during the formation of the outer conductor. v

The invention will now be more fully un'- 'derstood from the followindescription when read in connection wit the accom pan ing drawing inwhich Figure 1 is a sectional view showing the arrangement of the. twopieces of tubing comprisin the inner concentric conductor and theielectric sheet; Fi 2 shows these elements after being spira y twistedto form the core of the system; Fi 3 is a drawing showing how the out rc n u tor is rin d a d mounted 1980. I Serial No. 454,784.

conductor comprisingthe elements 1 and 1. -After the dielectric andsemi-circular tub-' ing elements have been mounted together, as shown inFig. 1, they are twisted into spiral form as indicated invFig. 2, t6form the core of the concentric conductor system. The outer conductormay be in the '10 form of a tube whose inner surface has a diametersufiicient to slide over the dielectric spiral element 2, but preferablyit is constructed from a sheet of flat conductive material 3 passedthrough a circular die 4 s0 76 that the two edges of the sheet arebrought together to form an outer tubular conductor 5. The inner core,comprisin the spiral dielectric 2 and semi-circular tu es 1 and 1', isfed into the outer conductor 5 during the 80 process of passing thesheet -3 through the die-4, so that the conductor may be made up inlengths as long as desired. Preferably, the abutting edges of the outertubular conductor 5 will be united by welding, solder- 35 ing or brazingto make the system watertight. If desired, however, the entire outerconductor may be covered by a sheath of lead or other material. on

In order to prevent slippage of the dielectric sheet 2 with respect tothe semi-circular tubes 1 and 1, these elements may be arranged as shownin Fig. 4 so that ribs are formed along the central axis of thedielectric sheet 2 and corresponding grooves, are provided in the flatsides of the semi-circular tubes 1 and 1'. By locating the ribs.of thedielectric element in the grooves of the semicircular sections oftubing, the parts will be 100 folded together and abutting each otherover 7 the other for a low frequency transmission system Withoutinterference with the relatively high frequency transmission taking 10place over the outer conductor 5 with the inner conductors 1 and 1'acting as a return therefor.

It will be obvious-that the general principles herein disclosed may beembodied in many other organizations widely different from thoseillustrated without departing from the spirit of the invention asdefined in the following claims.

What is claimed is:

1. A concentric conductor system including an inner conductor comprisingtwo pieces of conducting material of substantially semi-circularsection, with their flat sides abutting, and a. sheet of thin, flatdielectric material'located between and extending beyond. the flat sidesof the-two sections of tubing, said elements being twisted together toform a spiral core, and a tubular outer conductor mounted upon the edgesof. the spiral insulating element.

2. A concentric conductor system including an inner conductor comprisingtwo pieces of conducting material of substantially semi-circularsection, with their flat sides abutting, and a sheet of thin, flatdielectric material located between the flat sides of the two sectionsof tubing, said elements bein twisted together to form a spiral core, ana tubular outer conductor formed from a sheet of conductive materialhaving its edges the spira 1y arranged core.

3. A: concentric conductor system includmg 7 an inner conductorcomprising two pieces of conducting material of substantiallysemi-circular section, with their flat sides abutting, and a sheet ofthin, flat dielectric material located between and ex tending beyond theflatsides of thetwo sections of tubing, said elements being twistedtogether to form .a spiral core, and an outerconductor comprising asheet of conductive material wrapped about the spiral core and formed inthe shape'of a tube surrounding the spiral core and mounted on the edgesof the spiral dielectric sheet.

4. 'A concentric conductor system including .an inner conductorcomprising two pieces of conducting material of substantiallysemi-circular section, with their flat sides abutting, and a sheet ofthin, flat dielectric material located between and extending beyond theflat sides of the two sections'of tubing, said elements being twistedtogether to form a spiral core, and a tubular -May 1930.

an independent circuit for low frequency transmission. I

5. A concentric conductor system including an inner conductor comprlslngtwo pieces of conduct-ing material of substan-.

tially semi-circular section, with their flat sides abutting, and asheet of thin, flat dielectric 'material located between the flat sidesof the two sections of'tubing, said elements being twisted together toform a spiral core, and a tubular outer conductor formed from a sheet ofconductive material having its edges folded together and abutting eachother over the spirally arranged core so as to be separated from theinner conductor by gaseous space, the two semicircular tubes beingadapted to be connected in parallel to form the return for the outertubular conductor at high frequencies and said semi-circular innertubular conductors being adapted to be connected one as a return for theother to form an independent circuit for low frequencytransmission.

6. A concentric conductor system including an inner conductor comprisingtwo pieces of conducting material of substantially semi-circularsection, with their flat sides abutting, and a sheet of thin, fiatdielectric material located between and ex-' tending beyond the flatsides of the two sections of tubing, said elements being twistedtogether to form a spiral core, and an outer conductor comprising asheet of conductive material wrapped about the spiral core and formed inthe shape'of a tube surrounding the spiral core and mounted on the edgesof the spiral dielectric sheet so as to be separated from the innerconductor by gaseous space, the two semicircular tubes being adapted tobe connected in parallel to form the return for the outer tubularconductor at high frequencies and said semi-circular inner tubularconductors being adapted to be connected one as a return for the otherto form an independent circuit .for low fre quency transmission.

In testimony whereof, I have signed my name to this specification this16th day of ALLEN CARPE. In testimony whereof, I have signed my name tothis specification this 19th day "of May, 1930. FRANK- A. LEIBE. 1

